Saturday, April 2, 2011
The "Hygiene Hypothesis"
I'm taking a mini-med school course at UCSF on the Immune System. The "hygiene hypothesis" is a new way of thinking about allergies and asthma. We are essentially an ecosystem for bacteria, we have more "bacterial" cells, than "human" cells. The right kinds of bacteria can help regulate the immune system. Allergies and asthma are examples of the immune system overreacting to harmless substances like pet dander or pollen.We need to be exposed to a wide range of pathogens as young children to "educate" our immune system. Studies show that children living on farms, close to animals, have a lower rate of allergies and asthma, than children living in inner city environments. Short of living on a farm, growing up with pets, especially dogs (that sleep on your bed!) can lessen the chance of developing allergies or asthma. Another strategy for ingesting beneficial bacteria, is eating yogurt with live cultures or fermented foods like sauerkraut. We want a balanced immune system, one that can fight off dangerous viruses and bacteria, but not so overactive that it produces autoimmune conditions like eczema or allergies.